1. Field of the Invention
The present invention relates to a method of manufacturing a trim cover assembly covering the surfaces of vehicle seats, and in particular relates to a manufacturing method for the trim cover assembly in which a decoration, such as a letter or pattern, is applied to the surface of the trim cover assembly by means of high frequency wave welding method.
2. Description of Prior Art
Improvement on aesthetic effect for vehicle or automobile seats has been done by application of a decorative material, such as letters, or patterns, to the surface of a trim cover assembly. In most instances, conventional methods for effecting such decoration process, are based on either of the undermentioned ways:
Firstly, as shown in FIG. 1 of the accompanying drawings, there has been employed a printing method which includes a roll leaf hot stamping method or silk screening method in order to apply a decorative material to a surface of trim cover assembly (1a). Hereinafter, the surface of trim cover assembly shall be referred to as a substrate for simplicity sake. In this case, the decorative material is an ink (1b), and any desired decorative patterns or letters, with a multiplicity of colors, can be provided in a vivid fashion on the substrate (1a), without damage thereon. However, because of the ink (1b) being merely applied on the substrate (1a), a long period of wear causes abrasion of the ink (1b) and results in the impairment of the good-looking seat.
Secondly, as indicated in FIG. 2(A), a film of decorative material (1c) is placed on and welded to the substrate (1a) at a given welding area, at which time, simultaneously, the non-welded area thereof is cut off, so that the welded area of the film (1c) is left on the substare (1a), representing a decorative image thereuepon. In this prior art method, an upper die (a') used is of such construction that its working surface is formed in conformity with a desired decorative image, and a projected blade (a'1) is provided in a manner surrounding the woring surface. Therefore, during the processes, the film (1c) is cut in a predetermined contour and welded integrally with the substrate (1a), as seen in FIG. 2(B). The advantage is indeed found in no possibility of wear in regard to the decorative film (1c). However, the use of such intricate die (a'), which needs to be formed solely for each different desired images, increases costs involved. The blade (a'1) on the die (a') gives a flaw to the substrate (1a), which reduces the use life of the substrate (1a) (for example, a synthetic leather). Further, as the film (1c) is cut by the blade (a'1), it is highly possible that a burr will be created at the edges of the film (1c) and from such burr, the film (1c) will be peeled off.